Abstract: What is the importance of the decentralization of business services in a Parisian metropolitan region that is known for its inherited monocentricity? Using revised statistical and cartographic methodological tools, I try to answer two questions: Is the new Parisian metropolitan economic geography one of dispersal or of polycentricity? Does decentralization mean the decline or the reinforcement of the economic core? If secondary suburban economic centers benefit from the decentralization of business services, neighboring spaces of the municipality of Paris, such as the inner western suburbs of La Defense and Boulogne-Billancourt, are affected, too. This article demonstrates that polycentricity is not opposite to the constitution of a new golden triangle within the dense part of the agglomeration. This means both that economic centrality still matters (and thus that dispersed cities may not be the twenty-first century's metropolitan archetype) and that an enlarged core business district (CBD) straddling Paris and the western Hauts-de-Seine département is being reinforced (thus invalidating the theory of CBD decline). Thanks to the widening of the business district from Paris to La Defense, the labor market remains integrated; meanwhile, secondary economic centers in the Outer Suburbs tend to create fragmented subregional labor markets of their own.